Rotary expansible chamber device with variable eccentricity

ABSTRACT

A hydraulic transmission or speed-change device or the like, of the type comprising a stator, an input rotor to which an input shaft is connected, and an output rotor to which an output shaft is connected, with expansible chambers between adjacent pairs of these members, is characterized by a flexible annulus fixed against rotation relative to one of the members but radially deformable relative thereto. Deformation of the annulus is effected by means of fluid pressure jacks that actuate wedges in a direction parallel to the common axis of rotation. At least some of the relatively movable portions of at least some of the expansible chambers slide against this annulus with a stroke that varies as the deformation of the annulus.

United States Patent [191 Barnoud-Arnoulet [4 1 Aug. 5, 1975 ROTARYEXPANSIBLE CHAMBER DEVICE WITH VARIABLE ECCENTRICITY 21 Appl. No.:448,230

[30] Foreign Application Priority Data Mar. 5, 1973 France 73.07666 [52]US. Cl 418/31; 74/730 [51] Int. CI. ..F01C 21/10; F01C 21/16 [58] Fieldof Search 418/159, 22, 31; 192/58 R;

[56] References Cited UNITED STATES PATENTS 2,368,223 1/1945 Kendrick..4l8/31 2,842,064 7/1958 Wahlmank v.418/31 FOREIGN PATENTS ORAPPLICATIONS 1,073,662 9/1954 France 1,000,591 8/1965 United Kingdom..4l8/31 OTHER PUBLICATIONS W. H. Gibson & L. Fox, A New Development inHigh Speed Variable Delivery Vane Pumps, S.A.E. National Aeronautic andSpace Engineering Meeting, Los Angeles, Calif, 1970, (8 pages).

Primary Examiner-C. ,1. Husar Assistant E.\uminerL. J CasaregolaAttorney, Agent, or FirmYoung & Thompson [5 7] ABSTRACT A hydraulictransmission or speed-change device or the like, of the type comprisinga stator, an input rotor to which an input shaft is connected, and anoutput rotor to which an output shaft is connected, with expansiblechambers between adjacent pairs of these members, is characterized by aflexible annulus fixed against rotation relative to one of the membersbut radially deformable relative thereto. Deformation of the annulus iseffected by means of fluid pressure jacks that actuate wedges in adirection parallel to the common axis of rotation. At least some of therelatively movable portions of at least some of the expansible chambersslide against this annulus with a stroke that varies as the deformationof the annulus.

5 Claims, 3 Drawing Figures \y C 12 V w v .1 Y y 9.

, 1 ROTARY EXPANSIBLE CHAMBER DEVICE WITH VARIABLE ECCENTRICITY Thepresent invention relates to rotary expansible chamber devices of thetype in which relatively rotatable members have nonconcentric guidesurfaces for causing cyclic expansion and contractionof chambers intowhich the working fluid is drawn and from which the working fluid isexpelled. Devices of this type are well known as speed-change mechanismsor hydraulic transmissions or the like. One such mechanism to which thepresent invention is applicable is disclosed in my French Pat. No.1,073,662, to which reference will be had for further disclosure of theenvironment of my invention, thereby to avoid the need for such furtherdisclosure in the present application.

Devices of the type of the present invention comprise generally astator, a rotor connected to an input and another rotor connected to anoutput. Expansible chambers are formed between these elements, theelements having nonconcentric surfaces thereon such that upon relativerotation of the elements, the chambers will expand or contract therebyto admit and expel] the working fluid. It is of course well known insuch devices that r the greater is the eccentricity or nonconcentricityof the surfaces, the greater will be the volume of fluid flow, withcorresponding changes in the speeds and power ratios that areobtainable.

The present invention has as its object the provision of such a device,in which the displacement of the working fluid is readily regulable.

Another object of the present invention is the provision of such adevice which will be relatively simple and inexpensive to manufacture,easy to operate, maintain and repair, compact in configuration, andrugged and durable in use.

Briefly, the'objects of the invention are achieved by providing adeformable annulus connected to but radially movable relative to one ofthe three principal elements (stator, input rotor, output rotor),thereby to provide in effect a working surface on that associatedelement which is of variable curvature. Wedge means are provided,movable parallel to the common axis of rotation of the rotors to deformthe annulus. The deformation is symmetrical relative to the axis ofrotation and so the forces remain in balance.

In a preferred embodiment of the invention, the deformable annulus isprovided with blocks that slide in corresponding recesses in the numberwith which the annulus is associated. Wedge means are provided formoving the blocks in and out of their associated recesses in a mannerthat is symmetrical with respect to the axis of rotation, the wedgemeans moving in a direction parallel to that axis under the influence ofoperating means such as jacks such as fluid cylinders.

Actuation of the jacks to a controlled degree accordingly alters thecurvature of the deformable annulus to a corresponding degree, therebyto regulate the stroke of the expansible chambers and correspondingly toregulate the pressure and speed relationships of the device.

In a still more particular embodiment, the three principal elementsoverlap each other axially, the stator being outermost and the tworotors being innermost. The inner surface of the stator has inwardlyopening recesses in which sliding blocks are disposed for radialmovement, these blocks sliding on the outer surface of the flexibleannulus which has blocks secured to its inner surface that are receivedin recesses in the outer surface of the outer of th e two rotors, thetwo rotors having further recess and slidingblock assemblies betweenthemselves.

The invention may for example be embodied in a motor having a volumetricpump integral with a rotatable portion of the motor, thereby toconstitute a speed-change mechanism.

Other objects, features and advantages of thepresent invention .willbecome apparent from a consideration of the following description, takenin connection with the accompanying drawing, in which: i 1 1 FIG. 1 is aschematic axial view of a device according to the present invention;

FIG. 2 shows an enlarged cross section of one of the slide blocksbetween the flexible annulus and the surrounding stator; and

FIG. 3 is an enlarged cross-sectional view in the plane of the axis ofrotation, showing one of the wedge devices to vary the shape of theflexible. annulus.

Referring now to the drawing in greater detail, the device of thepresent invention comprises a stator 9 or outer ring in the form of anexterior cage, in which are concentrically disposed an input rotor 3 andan output rotor 13, which may be fixed either directly or throughsuitable speed-change devices (not shown) to input and output shafts(not shown) respectively.

A flexible annulus 1, for example of spring steeLis providedin axiallyoverlapping relationship with the members 3, 9 and 13 and has fixed toits inner surface four blocks 2 which slide in recesses provided inrotor 3. Two wedges 4 are provided in recesses in diametrically opposedblocks 2. Wedges 6 slide on wedges 4 and are actuated by stationaryfluid pressure jacks 7 that move members 8 parallel to the axis ofrotation. Members 8, in turn, are received in an annular ring 8' towhich the wedges 6 are secured, the ring 8" thus rotating with rotor 3.The degree to which jacks 7 are actuated by a source of fluid underpressure (not shown) thus regulates the eccentricity of annulus 1 bymoving the blocks 2 in or out of their recesses, the resilience of theannulus 1 maintaining wedges 4 and 6 in Contact with each other.

Stator 9 has recesses 9' which are of cylindrical cross section as bestseen in FIG. 2 and that have rounded edges. Segments 5 are disposed inrecesses 9' and are urged slidably against annulus l by springs 10 orother conventional devices such as magnets. Only a relatively smallsurface area of segments 5 is applied against annulus 1 thanks tocommunication opening 5' through segments 5 which balances the forcesand reduces friction.

The blocks 2 and the segments 5 near these blocks delimit between therotor 3 and the stator 9 four compartments. In each of thesecompartments, recesses or holes 1 through annulus 1 permit thecirculation of fluid such as hydraulic fluid. Canals 11 and 11 bring thefluid into two opposed compartments and canals l2 and 12' evacuate thefluid from the other two compartments. Lateral seals (not shown) arecarried by stator 9 on either side of the assembly and thus assurelateral fluid tightness.

The rotor 13 is concentric within rotor 3 and may with the rotor 13comprise a pump. In the illustrated embodiment, the pump has segments 14of the same type as the segments 5. The pump has an output flowproportional to the relative rotation of the tworotors. An oil inlet(not shown) through the shaft of rotor 13 supplies to the pumpsufficient fluid to make up losses. The operation of the deviceaccording to the present invention is as follows:

The output rotor 3 behaves as a rotatable piston and modifies the speedand force exerted by the input rotor 13 according to the eccentricity ofthe annulus l, which in turn is regulated by the FIG. 3 mechanism. Whenthe eccentricity, that is, the deformation from circular configuration,is at a maximum, the fluid flow is also at the maximum and the'speed isat a minimum. But when the annulus l is circular or nearly circular,then there is no substantial output flow from the pump and the rotor 3turns at substantially the same speed as the rotor 13, except of coursefor a small slippage due to losses. It would of course be possible toprovide an automatic interlock (not shown) for the two rotors, to ensuretheir conjoint rotation in this position, with no slippage. The jack 7can also unlatch the stator 9 at a predetermined point, so that thelatter can turn freely and thus reduce slippage.

Means (not shown) are of course provided for controlling the jack 7 tomodify the shape of annulus 1. Among these might of course be meansresponsive to the speed of the input shaft which would be detected andwould control the outflow of an auxiliary pump driven by the inputshaft. The detector would act on a distributor which would charge ordischarge the jack 7. Other such systems of course can be devised.

- From a-consideration of the foregoing disclosure, therefore, it willbe evident that all of the initially recited objects of the presentinvention have been achieved.

Although the present invention has been described and illustrated inconnection with a preferred embodiment, it is to be understood thatmodifications and variations may be resorted to, without departing fromthe spirit of the invention, as those skilled in this art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the present invention as defined by theappended claims.

Having described my invention, I claim:

1. A fluid transmission comprising an annular stator, a first annularrotor within said stator, a second rotor within said first rotor, aflexible annulus surrounding said first roto between said stator andsaid first rotor,

means defining between said annulus and said first.

rotor a plurality of expansible chambers, means defining between saidrotors spaced chambers that vary in volume upon relative rotation ofsaid rotors. said spaced chambers communicating through passagewaysthrough said first rotor with said expansible chambers, blocks securedto said annulus and slidable radially in recesses in said first rotorthereby to fix said annulus against rotation relative to said firstrotor, and means for deforming said annulus from circular form therebyto regulate the expansion and contraction of said expansible chambersupon rotation of said first rotor, said deforming means comprising meansbearing against said blocks to impart to said blocks a non-circular pathupon rotation of said first rotor.

2. A transmission as claimed in claim 1, said bearing means comprisingfluid pressure jacks that act in a direction parallel to the axis of therotor to urge wedges against said blocks.

3. A transmission as claimed in claim 1, and segments disposed incylindrical recesses in said stator and spring means urging saidsegments into sliding contact with the outer surface of said annulus.

4. A transmission as claimed in claim 3, each of said segments havingspaced lips thereon that bear slidably against said annulus.

5. A transmission as claimed in claim 1, said annulus having passagewaystherethrough for the circulation of fluid.

1. A fluid transmission comprising an annular stator, a first annularrotor within said stator, a second rotor within said first rotor, aflexible annulus surrounding said first roto between said stator andsaid first rotor, means defining between said annulus and said firstrotor a plurality of expansible chambers, means defining between saidrotors spaced chambers that vary in volume upon relative rotation ofsaid rotors, said spaced chambers communicating through passagewaysthrough said first rotor with said expansible chambers, blocks securedto said annulus and slidable radially in recesses in said first rotorthereby to fix said annulus against rotation relative to said firstrotor, and means for deforming said annulus from circular form therebyto regulate the expansion and contraction of said expansible chambersupon rotation of said first rotor, said deforming means comprising meansbearing against said blocks to impart to said blocks a non-circular pathupon rotation of said first rotor.
 2. A transmission as claimed in claim1, said bearing means comprising fluid pressure jacks that act in adirection parallel to the axis of the rotor to urge wedges against saidblocks.
 3. A transmission as claimed in claim 1, and segments disposedin cylindrical recesses in said stator and spring means urging saidsegments into sliding contact with the outer surface of said annulus. 4.A transmission as claimed in claim 3, each of said segments havingspaced lips thereon that bear sLidably against said annulus.
 5. Atransmission as claimed in claim 1, said annulus having passagewaystherethrough for the circulation of fluid.